Factors Affecting Stone-free Rate and Complications of Percutaneous Nephrolithotomy for Treatment of Staghorn Stone
Urology Department, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt. Urology
(Impact Factor: 2.19).
03/2012; 79(6):1236-41. DOI: 10.1016/j.urology.2012.01.026
To determine factors affecting the stone-free rate and complications of percutaneous nephrolithotomy (PNL) for treatment of staghorn stones.
The computerized database of patients who underwent PNL for treatment of staghorn stones between January 2003 and January 2011 was reviewed. All perioperative complications were recorded and classified according to modified Clavien classification system. The stone-free rate was evaluated with low-dose noncontrast computed tomography (CT). Univariate and multivariate statistical analyses were performed to determine factors affecting stone-free and complication rates.
The study included 241 patients (125 male and 116 female) with a mean age of 48.7 ±14.3 years. All patients underwent 251 PNL (10 patients had bilateral stones). The stone-free rate of PNL monotherapy was 56% (142 procedures). At 3 months, the stone-free rate increased to 73% (183 kidneys) after shock wave lithotripsy. Independent risk factors for residual stones were complete staghorn stone and presence of secondary calyceal stones (relative risks were 2.2 and 3.1, respectively). The complication rate was 27% (68 PNL). Independent risk factors for development of complications were performance of the procedure by urologists other than experienced endourologist and positive preoperative urine culture (relative risks were 2.2 and 2.1, respectively).
Factors affecting the incidence of residual stones after PNL are complete staghorn stones and the presence of secondary calyceal stones. Complications are significantly high if PNL is not performed by an experienced endourologist or if preoperative urine culture is positive.
Available from: Sung Yong Cho
- "Studies have reported predictive factors of SFR after PCNL, such as complete staghorn stones, presence of secondary calyceal stones, stones of high calcium phosphate composition, and low BMI , , . Recently, few research groups have developed prediction methods, and demonstrated advantages of predicting surgical outcomes of PCNL , . "
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ABSTRACT: The Seoul National University Renal Stone Complexity (S-ReSC) scoring system was developed to predict the stone-free rate (SFR) after single-tract percutaneous nephrolithotomy (PCNL). This study is an external validation of this scoring system.
A retrospective review included 327 patients who underwent PCNL at 2 tertiary referral centers. The S-ReSC score was assigned from 1 to 9 based on the number of sites involved. The stone free status was defined as either complete clearance or clinically insignificant residual fragments <4 mm in size at 1 month follow-up imaging. Inter-observer and test-retest reliabilities were evaluated. The statistical performance of the prediction model was assessed by its predictive accuracy, predictive probability, and clinical usefulness.
The overall SFR was 65.4%. SFRs were 83.9%, 47.6%, and 21.4% in low (1-2), intermediate (3-4), and high (5-9) score groups, respectively, with significant differences (P<0.001). Inter-observer and test-retest reliabilities revealed almost perfect agreements. External validation of the S-ReSC scoring system revealed an AUC of 0.731 (95% CI 0.675-0.788). The AUC of 3-titered S-ReSC score groups was 0.691 (95% CI, 0.629-0.753). The calibration plot showed that the predicted probability of SFR had a concordance comparable to that of the observed frequency. The Hosmer-Lemeshow goodness-of-fit statistic revealed an adequate performance of the predictive model (P = 0.10). Inter-observer and test-retest reliability showed a good level of agreement.
The S-ReSC scoring system is useful in predicting the post-PCNL SFR and in describing the complexity of renal stones.
Available from: Tarek Karamany
- "ND ND  RS 102 20 (19.6) ND 81 (79.5) ND 10 (9.8) 10 (9.8) 1 (1) 9 (8.8) 0 0 ND ND  RS 103 103 (100) 42 (40.7) 54 (52.5) "
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To evaluate a supracostal approach for percutaneous nephrolithotomy (PCNL) of staghorn calculi through a prospective study and review of previously reported cases.Methods
From June 2009 to November 2011, 40 patients with staghorn calculi were scheduled for supracostal S-PCNL in a prospective study. Of the 40 renal units, 16 (40%) had a complete staghorn and 24 (60%) had a partial staghorn calculus. Perioperative complications were stratified according to the modified Clavien system. Univariate and multiple logistic regression analyses were used to determine statistically significant variables affecting the stone-free rate and development of complications.ResultsIn all, 57 tracts were established in the 40 renal units; 23 (58%) renal units were approached through one supracostal upper pole calyx, while 13 (33%) and four (10%) required a second middle- or lower-pole puncture, respectively. Overall, 78% of patients were rendered stone-free or had clinically insignificant residual fragments with PCNL monotherapy, and this increased to 88% with auxiliary procedures. In the logistic regression analysis, a complete staghorn stone was the only independent variable for residual stones (P = 0.005). There was an overall complication rate of 38%. Independent variables with an influence on complications were staghorn stone burden (P = 0.007), and operative duration (P = 0.045).Conclusions
The supracostal upper calyceal approach provides optimum access for the percutaneous removal of staghorn stones. Appropriate attention to the technique and to monitoring before and after surgery can detect thoracic complications, and these can be managed easily with intercostal chest tube drainage, with no serious morbidity.
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